# -*- coding: utf-8 -*-

"""
***************************************************************************
    VoronoiPolygons.py
    ---------------------
    Date                 : August 2012
    Copyright            : (C) 2012 by Victor Olaya
    Email                : volayaf at gmail dot com
***************************************************************************
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU General Public License as published by  *
*   the Free Software Foundation; either version 2 of the License, or     *
*   (at your option) any later version.                                   *
*                                                                         *
***************************************************************************
"""

__author__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

from sets import Set

from PyQt4.QtCore import *
from qgis.core import *

from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import \
        GeoAlgorithmExecutionException
from processing.parameters.ParameterVector import ParameterVector
from processing.outputs.OutputVector import OutputVector
from processing.algs.ftools import voronoi
from processing.tools import dataobjects, vector


class VoronoiPolygons(GeoAlgorithm):

    INPUT = 'INPUT'
    OUTPUT = 'OUTPUT'

    # =========================================================================
    # def getIcon(self):
    #    return QIcon(os.path.dirname(__file__) + "/icons/voronoi.png")
    # =========================================================================

    def defineCharacteristics(self):
        self.name = 'Voronoi polygons'
        self.group = 'Vector geometry tools'

        self.addParameter(ParameterVector(self.INPUT, 'Input layer',
                          [ParameterVector.VECTOR_TYPE_POINT]))

        self.addOutput(OutputVector(self.OUTPUT, 'Voronoi polygons'))

    def processAlgorithm(self, progress):
        layer = dataobjects.getObjectFromUri(
                self.getParameterValue(self.INPUT))

        writer = self.getOutputFromName(
                self.OUTPUT).getVectorWriter(layer.pendingFields().toList(),
                                             QGis.WKBPolygon, layer.crs())

        inFeat = QgsFeature()
        outFeat = QgsFeature()
        extent = layer.extent()
        height = extent.height()
        width = extent.width()
        c = voronoi.Context()
        pts = []
        ptDict = {}
        ptNdx = -1

        features = vector.features(layer)
        for inFeat in features:
            geom = QgsGeometry(inFeat.geometry())
            point = geom.asPoint()
            x = point.x() - extent.xMinimum()
            y = point.y() - extent.yMinimum()
            pts.append((x, y))
            ptNdx += 1
            ptDict[ptNdx] = inFeat.id()

        if len(pts) < 3:
            raise GeoAlgorithmExecutionException(
                    'Input file should contain at least 3 points. Choose \
                    another file and try again.')

        uniqueSet = Set(item for item in pts)
        ids = [pts.index(item) for item in uniqueSet]
        sl = voronoi.SiteList([voronoi.Site(i[0], i[1], sitenum=j) for (j,
                              i) in enumerate(uniqueSet)])
        voronoi.voronoi(sl, c)
        inFeat = QgsFeature()

        current = 0
        total = 100.0 / float(len(c.polygons))

        for (site, edges) in c.polygons.iteritems():
            request = QgsFeatureRequest().setFilterFid(ptDict[ids[site]])
            inFeat = layer.getFeatures(request).next()
            lines = self.clip_voronoi(edges, c, width, height, extent, 0, 0)

            geom = QgsGeometry.fromMultiPoint(lines)
            geom = QgsGeometry(geom.convexHull())
            outFeat.setGeometry(geom)
            outFeat.setAttributes(inFeat.attributes())
            writer.addFeature(outFeat)

            current += 1
            progress.setPercentage(int(current * total))

        del writer

    def clip_voronoi(self, edges, c, width, height, extent, exX, exY):
        """Clip voronoi function based on code written for Inkscape.
        Copyright (C) 2010 Alvin Penner, penner@vaxxine.com
        """

        def clip_line(x1, y1, x2, y2, w, h, x, y):
            if x1 < 0 - x and x2 < 0 - x:
                return [0, 0, 0, 0]
            if x1 > w + x and x2 > w + x:
                return [0, 0, 0, 0]
            if x1 < 0 - x:
                y1 = (y1 * x2 - y2 * x1) / (x2 - x1)
                x1 = 0 - x
            if x2 < 0 - x:
                y2 = (y1 * x2 - y2 * x1) / (x2 - x1)
                x2 = 0 - x
            if x1 > w + x:
                y1 = y1 + (w + x - x1) * (y2 - y1) / (x2 - x1)
                x1 = w + x
            if x2 > w + x:
                y2 = y1 + (w + x - x1) * (y2 - y1) / (x2 - x1)
                x2 = w + x
            if y1 < 0 - y and y2 < 0 - y:
                return [0, 0, 0, 0]
            if y1 > h + y and y2 > h + y:
                return [0, 0, 0, 0]
            if x1 == x2 and y1 == y2:
                return [0, 0, 0, 0]
            if y1 < 0 - y:
                x1 = (x1 * y2 - x2 * y1) / (y2 - y1)
                y1 = 0 - y
            if y2 < 0 - y:
                x2 = (x1 * y2 - x2 * y1) / (y2 - y1)
                y2 = 0 - y
            if y1 > h + y:
                x1 = x1 + (h + y - y1) * (x2 - x1) / (y2 - y1)
                y1 = h + y
            if y2 > h + y:
                x2 = x1 + (h + y - y1) * (x2 - x1) / (y2 - y1)
                y2 = h + y
            return [x1, y1, x2, y2]

        lines = []
        hasXMin = False
        hasYMin = False
        hasXMax = False
        hasYMax = False
        for edge in edges:
            if edge[1] >= 0 and edge[2] >= 0:
                # Two vertices
                [x1, y1, x2, y2] = clip_line(
                    c.vertices[edge[1]][0],
                    c.vertices[edge[1]][1],
                    c.vertices[edge[2]][0],
                    c.vertices[edge[2]][1],
                    width,
                    height,
                    exX,
                    exY,
                    )
            elif edge[1] >= 0:
                # Only one vertex
                if c.lines[edge[0]][1] == 0:
                    # Vertical line
                    xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
                    if c.vertices[edge[1]][1] > (height + exY) / 2:
                        ytemp = height + exY
                    else:
                        ytemp = 0 - exX
                else:
                    xtemp = width + exX
                    ytemp = (c.lines[edge[0]][2] - (width + exX)
                             * c.lines[edge[0]][0]) / c.lines[edge[0]][1]
                [x1, y1, x2, y2] = clip_line(
                    c.vertices[edge[1]][0],
                    c.vertices[edge[1]][1],
                    xtemp,
                    ytemp,
                    width,
                    height,
                    exX,
                    exY,
                    )
            elif edge[2] >= 0:
                # Only one vertex
                if c.lines[edge[0]][1] == 0:
                    # Vertical line
                    xtemp = c.lines[edge[0]][2] / c.lines[edge[0]][0]
                    if c.vertices[edge[2]][1] > (height + exY) / 2:
                        ytemp = height + exY
                    else:
                        ytemp = 0.0 - exY
                else:
                    xtemp = 0.0 - exX
                    ytemp = c.lines[edge[0]][2] / c.lines[edge[0]][1]
                [x1, y1, x2, y2] = clip_line(
                    xtemp,
                    ytemp,
                    c.vertices[edge[2]][0],
                    c.vertices[edge[2]][1],
                    width,
                    height,
                    exX,
                    exY,
                    )
            if x1 or x2 or y1 or y2:
                lines.append(QgsPoint(x1 + extent.xMinimum(), y1
                             + extent.yMinimum()))
                lines.append(QgsPoint(x2 + extent.xMinimum(), y2
                             + extent.yMinimum()))
                if 0 - exX in (x1, x2):
                    hasXMin = True
                if 0 - exY in (y1, y2):
                    hasYMin = True
                if height + exY in (y1, y2):
                    hasYMax = True
                if width + exX in (x1, x2):
                    hasXMax = True
        if hasXMin:
            if hasYMax:
                lines.append(QgsPoint(extent.xMinimum() - exX, height
                             + extent.yMinimum() + exY))
            if hasYMin:
                lines.append(QgsPoint(extent.xMinimum() - exX,
                             extent.yMinimum() - exY))
        if hasXMax:
            if hasYMax:
                lines.append(QgsPoint(width + extent.xMinimum() + exX, height
                             + extent.yMinimum() + exY))
            if hasYMin:
                lines.append(QgsPoint(width + extent.xMinimum() + exX,
                             extent.yMinimum() - exY))
        return lines
